Alternative use of miRNA-biogenesis co-factors in plants at low temperatures (IF 5.413)

YONES, CRISTIAN; MILONE, DIEGO; RÉ, DELFINA A.; ARCE, AGUSTIN L.; MANAVELLA, PABLO A.; LANG, PATRICIA L. M.; STEGMAYER, GEORGINA

DEVELOPMENT

COMPANY OF BIOLOGISTS LTD

Año: 2019 vol. 146

0950-1991

Plants use molecular mechanisms to sense temperatures, trigger quick adaptiveresponses, and thereby cope with environmental changes. MicroRNAs (miRNAs) arekey regulators of plants? development under such conditions. The catalytic action ofDICER LIKE 1 (DCL1), in conjunction with HYPONASTIC LEAVES 1 (HYL1) andSERRATE (SE), produces miRNAs from double-stranded RNAs. As plants lack a stableinternal temperature to which enzymatic reactions could be optimized during evolution,reactions like miRNA processing, have to be adjusted to fluctuating environmentaltemperatures.Here, we report that with decreasing ambient temperature, the plant miRNAbiogenesis machinery becomes more robust, producing miRNAs even in the absence ofthe key DCL1 co-factors HYL1 and SE. This reduces the morphological andreproductive defects of se and hyl1 mutants, restoring seed production. With small RNAsequencing and bioinformatics analyses we identified specific miRNAs whoseproduction becomes HYL1/SE independent in response to temperature decrease, andfound that the secondary structure of primary miRNAs is key for this temperaturerecovery. This finding may have evolutionary implications as a potential adaptation-manuscriptdriving mechanism to a changing climate.